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j.urnal of Water Resource and Protection 2023年第6期15卷 299-314页

作者： nancy j. leland Kimberley Crocker Pearson Marty K. Burke j.ffrey T. Miller Alison Watts j.mes F. Haney Department of Biological Sciences University of New Hampshire Center for Freshwater Biology and Ecotoxicology Durham New Hampshire USA Lim-Tex North Andover Massachusetts USA Brewster Natural Resources Advisory Commission Brewster Massachusetts USA Brewster Ponds Coalition Brewster Massachusetts USA Department of Civil and Environmental Engineering University of New Hampshire College of Engineering and Physical Sciences Durham New Hampshire USA

We have verified the use of a serial filtration method to isolate picocyanobacteria for analysis. We used eDNA metabarcoding to confirm the picocyanobacteria as members of the Order Synechococcales, Genus Cyanobium, specifically Cyanobium 6307. Fluorometric analysis using accessory pigments phycocyanin and phycoerythrin described periods of excess biomass, where the net growth rate model confirmed these conditions. The total anatoxin-a concentrations in the picocyanobacterial sample ranged from 0.0074 - 6.41 μg·L-1 representing a 40-fold difference over the entire sampling season. Sampling frequency of every three days appeared to be an important factor in capturing these changes in anatoxin-a concentration. During a period of excess biomass, we were able to establish a linear correlation between cyanobacterial biomass and Anatoxin-a concentrations.

关键词： Picocyanobacteria Anatoxin-a eDNA Phycocyanin Phycoerythrin

Alternative Methods for Analysis of Cyanobacterial Populations in Drinking Water Supplies: Fluorometric and Toxicological Applications Using Phycocyanin

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j.urnal of Water Resource and Protection 2018年第8期10卷 740-761页

作者： nancy j. leland j.mes F. Haney Lim-Tex North Andover MA USA Department of Zoology University of New Hampshire Durham NH USA

The management of cyanobacteria and potential exposure to associated biotoxins requires the allocation of scarce resources across a range of freshwater resources within various j.risdictions. Cost effective and reliable methods for sample processing and analysis form the foundation of the protocol yielding reliable data from which to derive important decisions. In this study the utilization of new methods to collect, process and analyze samples enhanced our ability to evaluate cyanobacterial populations. Extraction of phycocyanin using the single freeze thaw method provided more accurate and precise measurements (CV 4.7% and 6.4%), offering a simple and cost-effective means to overcome the influence of morphological variability. In-vacuo concentration of samples prior to ELISA analysis provided a detection limit of 0.001 μg·L?1 MC. Fractionation of samples (?1) = ?0.279 + (1.368 ? Log PC (μg·L?1) while in an Aphanizomemon spp. dominant system Log MC (ng·L?1) = 0.385 + (0.449 ? Log PC (μg·L?1). These methods and sampling protocol could be used in other aquatic systems across a broader regional landscape to estimate the levels of microcystins.

关键词： Cyanobacteria Size Fractions Fluorometry Monitoring Phycocyanin Extraction

Trophic Interactions between Anadromous j.venile Alewife (<i>Alosa pseudoharengus</i>) and Cyanobacterial Populations in a Shallow Mesotrophic Pond

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Natural Resources 2020年第9期11卷 394-419页

作者： nancy j. leland Ryan A. Landon j.mes F. Haney Department of Zoology University of New Hampshire Durham NH USA Lim-Tex North Andover MA USA

Alosa pseudoharengus is an anadromous fish that migrates from marine to freshwaters to spawn. The early larval and j.venile forms are known to be planktivorous, where heavy feeding upon their preferred food source of ... 详细信息

Alosa pseudoharengus is an anadromous fish that migrates from marine to freshwaters to spawn. The early larval and juvenile forms are known to be planktivorous, where heavy feeding upon their preferred food source of large crustacean zooplankton often results in changes to composition and size structure within this trophic guild which in turn can result in shifts within the trophic spectrum and a classic trophic cascade. In this study of Lower Mill Pond, Brewster MA, we evaluated the feeding strategy of juvenile Alosa to determine whether juvenile alewife switches to feeding largely on cyanobacteria and whether cyanotoxins microcystin (MC) and β-methlyamino-L-alanine (BMAA) bioaccumulate in their muscle tissue. Within 15 - 30 days of their estimated spawning date, overexploitation of crustacean zooplankton resulted in a shift from planktivory to benthic detritivory for the majority of their life history, although this did not reduce their condition based on weight-length relationships (Log Wwt. = -5.503 + (3.101 × Log Length). Mean MC (0.003 μg·g-1

关键词： Cyanobacteria j.venile Alewife Cyanotoxins MC BMAA Bioaccumulation Trophic Spectrum

Evaluation of Size Structure in Freshwater Cyanobacterial Populations: Methods to Quantify Risk Associated with Changes in Biomass and Microcystin Concentrations

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j.urnal of Water Resource and Protection 2019年第6期11卷 810-829页

作者： nancy j. leland j.mes F. Haney Kristin Conte Karen Malkus-Benj.min Bryan Horsely Lim-Tex North Andover MA USA Department of Zoology University of New Hampshire Durham NH USA Manchester Water Works Manchester NH USA Town of Barnstable Barnstable MA USA Association to Preserve Cape Cod Dennis MA USA

Cyanobacterial populations in surface waters, including drinking water supplies and recreational waters, represent an ever present challenge for resource managers. As communities continuously respond to external and internal processes, dynamic profiles of composition, dominance, growth and toxigenicity emerge. In this study measures of size structure and biomass, quantified using light microscopy and fluorometry, were used to estimate microcystin concentrations through linear regression analysis. Toxigenic profiles using cyanobacterial biomass were developed for lakes dominated by Microcystis spp. and Dolichospermum spp., influenced by both genus-specific pigment concentrations as well as microcystin concentrations. Community composition (Log %MIC) and biomass were used to describe microcystin concentrations in mixed assemblages, where composition was the first input variable. The accessory photopigment phycocyanin was used to describe the linear relationship between the daily growth and net microcystin production rates in the bloom-forming Microcystis spp. samples, suggesting that this size-fractionated sample may provide indications of potential toxigenicity in the whole lake water sample. Future investigations using fluorometric evaluation of cyanobacterial populations could provide additional applications and metrics for use by resource managers to quantify risk association with elevated cyanotoxin concentrations.

关键词： Microcystis Dolichospermum Phycocyanin Microcystins Growth Rates

Diet variability of snappers(Teleostei:Lutj.nidae)in a bay-to-reef ecosystem of the Mexican Caribbean

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Water Biology and Security

Water Biology and Security 2024年第1期3卷 53-59页

作者： Leon Felipe Martínez-j.arez j.an j.Schmitter-Soto nancy Cabanillas-Teran Norman Mercado-Silva El Colegio de la Frontera Sur 77014ChetumalQuintana RooMexico Centro de Investigacion en Biodiversidad y Conservacion Universidad Autonoma del Estado de Morelos62209CuernavacaMorelosMexico

Fishes use environmental resources differently.Snapper ontogenic movements among coastal habitats lead to diverse diets.We investigated the diets of seven snapper species(Lutj.nus apodus,L.analis,L.griseus,L.j.cu,L.mahogoni,L.synagris,and Ocyurus chrysurus)in three interconnected coastal environments in the western Caribbean:Río Huach channel,Chetumal/Corozal bay,and the adj.cent Xcalak reef lagoon.These three encompass all habitats used by the seven species in the study area.Snapper diets were mostly composed of fish and crustaceans,but dominance of either group varied among the studied habitats;for example,fish were the main prey for L.apodus from the reef lagoon zone,but second in the bay.Snappers are piscivorous-invertivorous mesopredators;the species that relied the most on fishes were L.griseus and L.j.cu,whereas O.chrysurus preferred crustaceans.Stomach content results revealed a high degree of dietary overlap among species.Our findings suggested a tradeoff in relative weight between fish and crustaceans as the main food source of snappers at these connected areas,supporting the hypothesis of niche segregation.Our results can be used as a baseline to further our understanding of the ecology and differences in resource use by snapper species in an area undergoing important anthropogenic changes.

关键词： Resource partitioning Chetumal/Corozal bay Quintana Roo Trophic ecology

The minimal clinically important difference for gait speed in significant unilateral vestibular hypofunction after vestibular rehabilitation

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j.urnal of Otology 2023年第1期18卷 15-20页

作者： Isaac B.Thorman Brian j.Loyd Richard A.Clendaniel leland E.Dibble Michael C.Schubert School of Public Health Department of EpidemiologyJohns Hopkins UniversityUnited States School of Physical Therapy and Rehabilitation Science University of MontanaUnited States Department of Orthopedic Surgery Doctor of Physical Therapy DivisionAnd Department of Head and Neck Surgery&Communication SciencesDuke University Medical CenterUnited States Department of Physical Therapy&Athletic Training University of UtahUnited States Laboratory of Vestibular NeuroAdaptation Department of Otolaryngology e Head and Neck SurgeryJohns Hopkins UniversityUnited States Department of Physical Medicine and Rehabilitation Johns Hopkins UniversityUnited States

Gait speed is a valid measure of both physical function and vestibular health.Vestibular rehabilitation is useful to improve gait speed for patients with vestibular hypofunction,yet there is little data to indicate how changes in gait speed reflect changes in patient-reported health outcomes.We determined the minimal clinically important difference in the gait speed of patients with unilateral vestibular hypofunction,mostly due to deafferentation surgery,as anchored to the Dizziness Handicap Index and the Activities Balance Confidence scale,validated using regression analysis,change difference,receiveroperator characteristic curve,and average change methods.After six weeks of vestibular rehabilitation,a change in gait speed from 0.20 to 0.34 m/s with 95%confidence was required for the patients to perceive a significant reduction in perception of dizziness and improved balance confidence.

关键词： Vestibular hypofunction Gait speed Minimal clinically important difference

Drought events influence nutrient canopy exchanges and green leaf partitioning during senescence in a deciduous forest

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Forest Ecosystems 2024年第1期11卷 110-119页

作者： j.Touche C.Calvaruso P.De Donato M.-P.Turpault INRAE BEFF-54000NancyFrance UMR 7359 GeoRessourcesFaculte des Sciences-Campus des Aiguillettes54506Vandoeuvre Les NancyFrance EcoSustain Environmental Engineering OfficeResearch and DevelopmentKanfen57330France

The increase in the frequency and intensity of drought events expected in the coming decades in Western Europe may disturb forest biogeochemical cycles and create nutrient deficiencies in trees.One possible origin of nutrient deficiency is the disturbance of the partitioning of the green leaf pool during the leaf senescence period between resorption,foliar leaching and senesced leaves.However,the effects of drought events on this partitioning and the consequences for the maintenance of tree nutrition are poorly documented.An experiment in a beech forest in Meuse(France)was conducted to assess the effect of drought events on nutrient canopy exchanges and on the partitioning of the green leaf pool during the leaf senescence period.The aim was to identify potential nutritional consequences of droughts for trees.Monitoring nutrient dynamics,including resorption,chemistry of green and senesced leaves,foliar absorption and leaching in mature beech stands from 2012 to 2019 allowed us to compare the nutrient exchanges for three nondry and three dry years(i.e.,with an intense drought event during the growing season).During dry years,we observed a decrease by almost a third of the potassium(K)partitioning to resorption(i.***.resorption efficiency),thus reducing the K reserve in trees for the next growing season.This result suggests that with the increased drought frequency and intensity expected for the coming decades,there will be a risk of potassium deficiency in trees,as already observed in a rainfall exclusion experiment on the same study site.Reduced foliar leaching and higher parititioning to the senesced leaves for K and phosphorus(P)were also observed.In addition,a slight increase in nitrogen(N)resorption efficiency occurred during dry years which is more likely to improve tree nutrition.The calcium(Ca)negative resorption decreased,with no apparent consequence in our study site.Our results show that nutrient exchanges in the canopy and the partitioning of the green leaf pool can be modified by drought events,and may

关键词： Natural drought Beech forest Canopy Resorption Foliar leaching Senesced leaves Nutrition

Complexity of Inj.ctive Homomorphisms to Small Tournaments, and of Inj.ctive Oriented Colourings

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Open j.urnal of Discrete Mathematics 2023年第1期13卷 1-15页

作者： Russell j. Campbell nancy E. Clarke Gary MacGillivray University of the Fraser Valley Abbotsford British Columbia Acadia University Wolfville Nova Scotia University of Victoria Victoria British Columbia

Several possible definitions of local inj.ctivity for a homomorphism of an oriented graph G to an oriented graph H are considered. In each case, we determine the complexity of deciding whether there exists such a homomorphism when G is given and H is a fixed tournament on three or fewer vertices. Each possible definition leads to a locally-inj.ctive oriented colouring problem. A dichotomy theorem is proved in each case.

关键词： Inj.ctive Graph Homomorphism Oriented Colouring Complexity

SARS-CoV-2 triggers Dickkopf-1(Dkk-1)modulation of T helper cells and lung pathology in mice

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Genes & Diseases 2024年第4期11卷 9-12页

作者： Yifan Wu Freedom M.Green Stephen A.Shaw Lauren j.Bonilla Shannon E.Ronca Maria Elena Bottazzi Farrah Kheradmand j.ll E.Weatherhead Department of Pathology&Immunology One Baylor PlazaHoustonTX 77030USA Department of Pediatrics One Baylor PlazaHoustonTX 77030USA Department of Medicine One Baylor PlazaHoustonTX 77030USA National School of Tropical Medicine One Baylor PlazaHoustonTX 77030USA Molecular Virology&Microbiology One Baylor PlazaHoustonTX77030USA Biologyof Inflammation Center Baylor College of MedicineOne BaylorPlazaHoustonTX77030USA Michael E.DeBakey VA Center for Translational Research on Inflammatory Diseases HoustonTX 77030USA

Severe acute respiratory syndrome coronavirus 2(SARSCov-2)is the etiologic agent of the coronavirus disease 19(COVID-19)pandemic.In viral infections like SARS-CoV-2,a robust anti-viral type 1 immune response,including upregulation of type 1 CD4+T helper cells(Th1),is required for effective viral clearance while minimizing end-organ pathology and collateral tissue damage.

关键词： pathology acute respiratory

Hepatic transcriptome profiling reveals early signatures associated with disease transition from non-alcoholic steatosis to steatohepatitis

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Liver Research 2022年第4期6卷 238-250页

作者： nancy Magee Forkan Ahamed Natalie Eppler Elizabeth j.nes Priyanka Ghosh Lily He Yuxia Zhang Department of Pharmacology Toxicology and TherapeuticsUniversity of Kansas Medical CenterKansas CityKSUSA Liver Center University of KansasKansas CityKSUSA

Background and aim:Non-alcoholic fatty liver disease(NAFLD)is becoming a leading cause of chronic liver disease worldwide.The molecular events that influence disease progression from non-alcoholic fatty liver(NAFL)to aggressive non-alcoholic steatohepatitis(NASH)remain incompletely understood,leading to lack of mechanism-based targeted treatment options for NASH.This study aims to identify early signatures associated with disease progression from NAFL to NASH in mice and humans.Materials and methods:Male C57BL/6j.mice were fed a high-fat,-cholesterol,and-fructose(HFCF)diet for up to 9 months.The extent of steatosis,inflammation,and fibrosis was evaluated in liver tissues.Total RNA sequencing(RNA-seq)was conducted to determine liver transcriptomic changes.Results:After being fed the HFCF diet,mice sequentially developed steatosis,early steatohepatitis,steatohepatitis with fibrosis,and eventually spontaneous liver tumor.Hepatic RNA-seq revealed that the key signatures during steatosis progression to early steatohepatitis were pathways related to extracel-lular matrix organization and immune responses such as T cell migration,arginine biosynthesis,C-type lectin receptor signaling,and cytokine-cytokine receptor interaction.Genes regulated by transcription factors forkhead box M1(FOXM1)and negative elongation factor complex member E(NELFE)were significantly altered during disease progression.This phenomenon was also observed in patients with NASH.

关键词： Liver Transcriptome Steatosis Inflammation Fibrosis Non-alcoholic steatohepatitis(NASH)